TSLP is a hemopoietic protein that is expressed in the heart, liver and prostate. TSLP overlaps biological activities with IL-7 and binds with the heterodimeric receptor complex consisting of the IL-7R alpha chain (IL-7Rª) and the TSLP-specific chain (TSLPR). Like IL-7, TSLP induces phosphorylation of STAT3 and STAT5, but uses kinases other than the JAKs for activation. TSLP prohibited apoptosis and stimulated growth of the human acute myeloid leukemia (AML)-derived cell line MUTZ3. It induces the release of T cell-attracting chemokines TARC and MDC from monocytes and activates CD11c(+) dendritic cells (DCs). TSLP activated DCs primed naive T cells to produce the proallergic cytokines (IL-4, IL-5, IL-13, TNFª) while down-regulating IL-10 and IFN-I³ suggesting a role in initiating allergic inflammation.

Fully biologically active when compared to standard. The ED50 as measured by its ability to induce proliferation of human IL-7Rª and human TSLP R co-transfected mouse BaF3 cells is less than 0.3 ng/ml, corresponding to a specific activity of > 3.3x106 units/mg.

Storage

This lyophilized preparation is stable at 2-8 C, but should be kept at -20 C for long term storage, preferably desiccated. Upon reconstitution, the preparation is stable for up to one week at 2-8 C. For maximal stability, apportion the reconstituted preparation into working aliquots and store at -20 C to -70 C. Avoid repeated freeze/thaw cycles.

We recommend that this vial be briefly centrifuged prior to opening to bring the contents to the bottom. Reconstitute in sterile distilled water or aqueous buffer containing 0.1% BSA to a concentration of 0.1-1.0 mg/mL. Stock solutions should be apportioned into working aliquots and stored at < -20 °, C. Further dilutions should be made in appropriate buffered solutions.

Physical Appearance

Sterile Filtered White lyophilized (freeze-dried) powder.

Usage

This material is for research, laboratory or further evaluation purposes. NOT FOR HUMAN USE.